Question though. If Sidious used force lightning on Vader prior to Vader burning up on Mustafar in ROTS, and we know after Mustafar Vader could not use FL because of his limbs and the damage it would do to his suit, would Sidious/Emperor really have zapped him for failing knowing it would short out his life support machines and thus killing him?

I ask because I too have the Emperor and Vader set up this way and now think I have to rethink this issue having read the novelization of ROTS. Thoughts?